In the past, various types of handrails suitable for use with moving walkways have been proposed, including handrails suitable for use with accelerating and decelerating moving walkways. While useful in some environments, previously proposed moving walkway handrails designed to be used with accelerating and decelerating moving walkways have had a number of disadvantages. For example, it has been difficult to design such handrails so that their acceleration and deceleration exactly corresponds to the acceleration and deceleration of the walkway with which they are to be used. Another problem with prior art handrails, particularly those suitable for use with accelerating and decelerating moving walkways, is that they provide only very limited amounts of acceleration and deceleration--see U.S. Pat. Nos. 3,796,161, entitled "Handrails For Passenger Conveyors" and 3,842,961, entitled "Variable Speed Handrails". Other types of conveyor handrails, such as the ones described in U.S. Pat. No. 3,714,902 entitled "Conveyor Handrails" use an overlapping element approach to provide larger amounts of acceleration and deceleration. While such handrails have improved acceleration and deceleration capability, the mechanical mechanisms for creating the acceleration and deceleration by changing the amount of element overlap are not entirely satisfactory.
Additionally, it is often desired to place accelerating and decelerating moving walkways and the related accelerating and decelerating handrails in existing building corridors, such as the corridors of an aircraft terminal, without modifying the corridors. To accomplish this result, it is necessary that the vertical silhouette of the handrail be relatively low and the horizontal silhouette be relatively narrow. Frequently, prior art handrails cannot meet these requirements.
One attempt to overcome the disadvantages of prior art accelerating and decelerating handrails discussed above is described in U.S. Pat. No. 4,240,537 entitled "Accelerating and Decelerating Handrail" by Phillip E. Dunstan. While the handrail described in U.S. Pat. No. 4,240,537 overcomes many of the disadvantages of the prior art handrails noted above, it is still more complicated than desirable. Moreover, it includes a drive mechanism that creates undesirably high reaction forces through the handrail acceleration and deceleration mechanism. More specifically, the handrail described in U.S. Pat. No. 4,240,537 includes an acceleration and deceleration mechanism coupling the handrail elements together and for controlling handrail element overlap that comprises a plurality of extendable and retractable members and a plurality of curved rigid cam follower arms. The cam follower arms are pulled by drive mechanisms located along short sections of the overall handrail path of travel, rather than along a substantial portion of the handrail path of travel. Thus, relatively high reaction forces are created in the coupling and overlap control elements. Hence, while the handrail described in U.S. Pat. No. 4,240,537 is an improvement over earlier handrails, it is subject to further improvement.